text:
During "partial panel" flying, in what ways is a turn rate indicator more useful than a turn coordinator?
This question deals with flying by reference to old-fashioned "steam gauges", not a modern "glass cockpit".
I recall hearing some pilots very experienced (ATP) pilots advocate for the older-style "turn rate indicator" (senses rotation about the aircraft's up/down axis) over the newer-style "turn coordinator" (senses rotation around an axis canted about 35 degrees from vertical, to sense roll as well as yaw.)  Specific reasons were given, but I don't recall them. In what ways is a turn rate indicator more useful than a turn coordinator, during "partial panel" flying (no working attitude indicator or heading indicator) in clouds?
The purpose of canting the gyro's axis of rotation to sense roll as well as yaw is to give an earlier warning to the first stages of a developing bank and turn, and in my experience this is indeed helpful, but apparently there are some drawbacks as well.

There is some related content in this answer -- https://aviation.stackexchange.com/a/81919/34686

A turn coordinator's axis of rotation is tilted around 30 degrees and rotates in the opposite direction. Because of this, looping errror is reversed and it under-reads at more than 1g. This makes it essentially useless when recovering from an unusual attitude on instruments, which is one situation in which you can easily find yourself when flying partial-panel.
With a turn rate indicator the instrument will over-read when the pilot is pulling excess G's in a turn; all the pilot has to do is relax the backpressure on the stick or yoke to correct.

Well, I can say in the situation where I really really wished I had a working turn rate indicator or turn coordinator, there was definitely a strong G-load.

Re the effects of "looping error" in the turn rate indicator versus the turn coordinator-- Is it really inherent in the concept of tilting the gyro axis to sense roll as well as yaw, that the gyro must spin in the opposite direction in the (canted) "turn coordinator" as in the (non-canted) "turn rate indicator"? If so, why?  And if not, why did the designers of the turn coordinator choose to do this?  Perhaps this would be appropriate as an actual question.

Re the concept of "looping error", this post may possibly be of some interest-- apparently if the springs that try to hold the gyro axis fixed relative to the aircraft are stiff enough, "looping error" can be greatly reduced-- https://www.pprune.org/tech-log/528255-turn-rate-indicator-turn-coordinator-looping-error.html?highlight=turn+rate+indicator+turn+coordinator+looping+error#post8337851

Never mind my comments about the direction of rotation of the gyro of the Turn Coordinator-- I think what you describe may be the norm but apparently it is not always that way-- I made a new question about it -- https://aviation.stackexchange.com/questions/81983/in-various-different-makes-and-models-of-turn-coordinators-do-the-gyro-wheels/81988#81988

Care to comment on this answer -- esp if you have definite knowledge that some turn coordinator gyros do (or did) indeed spin CCW rather than CW as viewed from the right, i.e. opposite the direction of the gyro in a turn rate indicator?   https://aviation.stackexchange.com/questions/81983/in-some-turn-coordinators-does-the-gyro-spin-opposite-to-the-direction-it-spi

You have the yaw/roll switched.  The TC's canted gyro adds roll to the yaw rate sensing, not the other way around.
The biggest drawback to the turn coordinator was the presentation of the aircraft, which to someone new to its use can tend to get mentally processed as a horizon bar, especially an old timer trained on aircraft with war surplus black face artificial horizons (with were widely installed on light aircraft into the 60s until surplus stocks ran out).  The TC's little airplane tilting left could initially be mentally interpreted as a bank to the right in other words, until your conscious brain finished processing the information (Russian artificial horizons had this presentation where the gyro tilted an airplane symbol; transitioning to western style horizons can be a problem for Russian pilots).
A turn and  bank with the vertical needle is easier to interpret at a glance.  The problem with the turn and bank was since only yaw rate information was presented, and there is no internal damping, in bumpy air you ended up with too much "noise" in the information presented from the nose wagging back and forth. In an airplanes like V tail Beech Bonanza, which were quite bad for tail wagging in turbulence, a regular turn and bank could be nearly useless in the bumps with the needle slewing back and forth constantly in level flight.  TCs avoid this by not just splitting the motion sensing between roll and yaw, but also by using internal dampers (little shock absorbers) to present only movement that is established.
One problem with TCs is that once you are stabilized in a turn, there is no more roll rate to sense, only turn rate and that has to be taken into account in the way the rate markings are placed.
My old '68 Cardinal had a TC that had gone bad because the internal damper had gone south.  The thing jumped around like crazy because of the un-damped sensitivity to both roll and yaw.  I replaced it with an older 12v electric turn and bank (way cheaper - Turn Coordinators are quite expensive because they are electric with internal inverters to convert 12vdc to 110v/400 Hz fixed frequency ac for the gyro) and found I had a strong preference for the vertical needle presentation.
Personally, I think the turn coordinator should have stuck with the vertical turn needle presentation, but with the damped canted gyro internals. Like I said, much easier to interpret at a glance.

Yes, thank you, re yaw/ roll switching

I definitely agree re ease of interpretation at a glance.

PS look at this piezoelectric turn rate indicator-- do you see the problem with the unmodified display on the left-- the pilot has to remember that the LED lights are supposed to represent the wingtips of the aircraft, NOT the horizon-- it is kind of backwards from a conventional "turn coordinator", which uses a somewhat similar display face.  The other device shown at the end of the video may be mounted either flat to sense pure yaw, or tilted to mix  roll sensing -- I prefer the latter.  https://vimeo.com/64331923

Yeah that's even worse, although he's invented a great gadget.  Imagine how instantly recognizable the indication would be with just a vertical pointer moving right for right turn and left for left turn.

You'd be the first person I know who prefers the vertical needle indication. The tilting airplane is much more obvious for interpretation, even if you don't know exactly what it means. But both are 'good' in the sense that to 'fix the problem', you counteract (oppose) the indication with the stick/yoke. That's how all indication should be, because in a stress we instinctively behave that way. This is why Russian pilots have big problems with the 'western' (direct) AI while western pilots never have problems with the 'Russian' (reverse) AI. (And why the @quiet's indicator is just horrible).

It's the fact that the turn needle presentation is more clear, enough that you can pick up movement of the needle in your peripheral vision.  Very few pilots have ever used an old style turn and bank as they are pretty rare now.

If you knew me, Zeus, then John K  would be the second as I agree w/ him.  One confusing thing about the turn coordinator is that the symbolic airplane tilts in the opposite direction as the horizon line on an attitude indicator, so a pilot who is used to mainly relying on an attitude indicator may tend to unconsciously interpret the tilting of something that looks sort of like a horizontal line (e.g. the symbolic airplane on the turn coordinator) as an indication of a bank in the opposite direction as actually exists.

Re comment above, I'm speaking from my real-world impressions practicing under the hood.  I see something tilting in the opposite direction as I'm used to seeing the horizon line of the attitude indicator tilt in the same situation, and I find it a little confusing.  That's my personal experience. I've also flown aircraft w/ the older style display and found it easier to interpret-- though again I'll say I did appreciate what seemed to me to be the larger initial indication for a given small initial roll rate away from wings-level, of the turn "coordinator" w/ canted gyro..

PS if you are flying an aircraft that typically experiences a great deal of adverse yaw as it starts to roll into a turn, that's when the benefits of the canted gyro axis really hit home.  Piezoelectric sensors don't suffer suffer from the G-loading issue described in another answer so if that's what you are using then you eliminate that potential drawback.  Sorry getting a bit off track from the original question here.

@John, very few, really? In all the airplanes I flew (which are mostly single-engine Cessnas and Pipers, i.e. not particularly new, but that's perhaps a dozen airframes) I remember seeing the vertical needle only once.

@quietflyer, I trust you, and I admitted the combination of this indication with the conventional AI (horizon) may be confusing. But in an ideal world, we would be changing the AI indication. Enough research have been done to prove that the reverse indication is better.

Interesting- I never thought of that.  What, the plane moves an the horizon stands still?  Like you are flying an RC plane?  Wouldn't some people find that confusing when inverted?  I guess nothing is actually reversed while inverted so...

Some other reasons a turn coordinator is less useful than a turn rate indicator--

Due to the fact that the axis of the gyro is canted to sense roll as well as yaw, a turn coordinator cannot be calibrated to read accurately for all combinations of airspeed and bank angle.
In an inverted spin, the direction of roll is opposite the direction of yaw, so a "turn coordinator" with the canted axis of sensing may either give an indication of a turn into the direction of spin, or the opposite. For some discussion of this see https://www.pprune.org/archive/index.php/t-56241.html


text:
What is meant by "Control your descent with throttle when landing, not with pitch"
I have heard it said on several occassion that when you are landing you need to control your descent with your throttle, and not with your pitch.
Two closely related questions that I think can be answered in one go:

Why do we use throttle instead of pitch to control the descent?
How does this work in practical terms?  (How do you do it?)

Oops, good catch.  I didn't see that one pop up on the list of possible dupes when I was writing the question...

This is a different way of wording the question, and since it didn't pop up in the possible duplicates, it would be good to leave open as a "sign post" to help others find the original question.  I wouldn't delete it if I were you!

@Lnafziger Ah...well, I guess so long as people know that it's a sign post and that I'm not actually lazy...

Your pitch is adjusted to maintain airspeed, whereas throttle and thrust are used to establish a rate of descent.
Shameless steal from KeithS comment below:

[Y]ou're gliding down to the runway, but you need a little engine power to keep a shallow glide slope because you aren't in an actual glider. The real explanation is that trying to use pitch to control glide slope causes dramatic changes in angle of attack, especially at the lower speeds used for approach and landing. This could cause a stall, or a severe loss of altitude. The throttle provides much more minute control over your angle of attack and thus your glide slope.

Right, I'm asking why because it sounds really counter intuitive.

It does, until you come to think of a landing as being a powered glide. That's more or less what it is; you're gliding down to the runway, but you need a little engine power to keep a shallow glide slope because you aren't in an actual glider. The real explanation is that trying to use pitch to control glide slope causes dramatic changes in angle of attack, especially at the lower speeds used for approach and landing. This could cause a stall, or a severe loss of altitude. The throttle provides much more minute control over your angle of attack and thus your glide slope.

@KeithS Shameless stealing of your comment, but proper attribution. I hope you don't mind :)

It's not about more minute control, it's about the fact that you are trying to manage your energy and your energy balance can only be changed by throttle. Elevators only control distribution of the energy between potential (altitude) and kinetic (speed).

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


text:
How does one launch unmanned high-altitude balloons without posing a safety risk to aviation?
How can people launch balloons privately (filled with helium or hydrogen) that reach the altitude of 30,000 feet? Isn't that a safety risk in the same way as geese?

It is definitely a security risk and can lead to incidents like TAM A319 near Rio de Janeiro on Jun 17th 2011, airborne contact with hot air balloon causes unreliable speeds. Unmanned aircraft is still an aircraft and all regulations apply!

Unmanned balloons can indeed create a safety risk for aircraft. An aircraft could collide with the balloon itself (as described in the case that Jan Hudec posted in his comment), or with the balloon's payload (see the FAA's AIM section 7-5-4 for general comments on this).
But it's important to note that unmanned balloons are (or should be) launched only after appropriate preparation and communication; most countries have some sort of regulations to follow. In the US (for example), 14 CFR 101 governs unmanned balloon launches and it includes the following requirements:

Launches must be in (mostly) clear skies and away from airports and built-up areas
The balloon must have a radar reflector and lights (if launched at night)
ATC must be informed in advance of the balloon launch, expected path etc.
The operator must track the balloon's position and descent and report them to ATC as needed

In other words, the balloon should be as visible as possible - both visually and on radar - and ATC should know where it is. That gives pilots a way to see and avoid the balloon and ATC can provide warnings and/or avoidance instructions to aircraft directly where possible, which is actually fairly similar to how aircraft avoid other aircraft.
Of course, there may be cases where someone launches a balloon without following those rules (or the local equivalents in another country). That would create a much higher safety risk but it would be illegal and the operator would be risking penalties for doing it.

This is a bit too specific to US regulations.

High altitude balloons reach more like 30km rather than kft. This means that there's a limited time in which they can interfere with normal aviation traffic (which, during cruise, is usually in a fairly narrow band between 8-12km).
Outside of cruise can be more of a problem (i,e: When landing or taking-off). For that reason it's essential to launch from somewhere far from an airport, so that the balloon can ascend in a location where it will not affect air traffic. Most countries also require you to inform air traffic control in advance of a balloon launch so that they can issue a warning (NOTAM) to pilots that lets them know to be aware of balloon activity.
Lastly, one can reduce the risk to aviation by constructing the balloon payload carefully. The balloon itself doesn't pose much of a risk but a heavy/dense payload can. To reduce the risk lightweight components should be used and dense items like batteries kept to a minimum. Most countries also have rules governing the size and weight of the balloon that you can launch.
For balloons that can't meet the rules (too heavy, need to launch near an airport, etc) there's two choice:
1) Don't launch.
2) Perform a much more extensive risk analysis and actively divert air traffic away from the balloon. This requires air traffic control to be able to see the balloon (using a radar reflector or, more usually, a transponder). Because of the cost of this option it's normally only very important or high-value payloads that are sent this way (such as NASA's research balloons).

High altitude balloons going into commercial airspace that are large enough to be a threat to a plane require a NOTAM to be issued and even small balloon launches are encouraged to have a NOTAM. Also, a weather balloon will not spend very much time in the danger zone but will drift right through it, so the exposure is brief. Most commercial fights occur along well-known corridors and flight paths. Balloons are often launched far away from those lines of travel. Just that alone makes it pretty safe. Small planes do the same thing: stay away from commercial flight corridors.

As for the TAM flight, that does not sound like a High Altitude weather balloon.  That sounded like an unmanned hot air balloon carrying a big banner.  I am guessing, based on the article that it was designed to stay at a lower altitude so people could see the banner.  High altitude weather balloons are like giant party balloons, very thin latex usually.  They generally rise at 1000 ft/min and are out of busy airspace quite quickly.  The payloads are limited to 12 lbs, but usually much lighter.  Mine was just over 2 lbs. If the regulations are followed there is very little risk.

 Good luck, do your research, and have fun.

Fascinating, Tom - say why don't you include some sort of telephone or something on the device which calls home when it lands and gives you the GPS location?  (all that would cost like $10 these days, I'm sure adding only a tiny amount to the cost.)  What's the deal on that? Cheers

Also relevant: there are other considerations. Its generally acceptable to launch small experimental payloads (ie simple telemetry + call sign transmitter on a permitted ISM band) as long as the total uninflated weight is below the limit for a Class 1 drone ie <250g.
The radar reflector must be a specified size and shape, connected to the balloon via something that can be readily detached in an emergency ie low melting point alloy + shielded nichrome U shaped cut-down and designed in such a way to prevent a hazard to anyone on the ground or in the air by limiting descent speed below 20fps.
Ideally also with a hyperbright green LED integrated into the reflector to indicate its in descent phase if at night.

Welcome to Av.SE! Can you link to the source of these requirements so that those who are interested have the authoritative document & not only "an internet post" to work from?

Are pilots educated that a green light represents a descending object?

How does one launch unmanned high-altitude balloons without posing a
safety risk to aviation?

By using some common sense, and not relying entirely on the regulations to ensure safety.
In the US, FAR 101 governs free balloon operations.  Note the requirement to notify ATC before launching.
One odd "loophole"-- it's arguably permissible to operate an unmanned free balloon in the surface-level Class E "extensions" (E3/E3a/E4 airspaces) that are adjoined to the inner core airspace areas of some airports for the purpose of protecting the instrument approaches.  You'd want to use a great deal of caution, and only do so in good weather conditions, and only at airports that don't have scheduled airline service, since the scheduled airlines tend to use the instrument approaches regardless of the prevailing weather conditions.
The relevant FAR reads:

§101.33   Operating limitations. No person may operate an unmanned
free balloon—
(a) Unless otherwise authorized by ATC, below 2,000 feet above the
surface within the lateral boundaries of the surface areas of Class B,
Class C, Class D, or Class E airspace designated for an airport;

Here are four FAA issuances that do not directly pertain to balloons per se, but that do construe that language like "within the lateral boundaries of the surface areas of... Class E airspace designated for an airport" does not include surface-level Class E "extensions" (E3/E3a/E4 airspaces):

FAR 107.41 states

No person may operate a small unmanned aircraft in Class B, Class C,
or Class D airspace or within the lateral boundaries of the surface
area of Class E airspace designated for an airport unless that person
has prior authorization from Air Traffic Control (ATC).

A memorandum issued on January 8, 2018 by FAA staffer Scott J. Gardner, Acting Manager, Emerging Technologies, AJV-115, stated that according to the FAA's Airspace Designations and Reporting Points document, "The only type of Class E airspace that matches the language in 107.41" is E2 airspace.  The memorandum stated:

In reviewing Class E Surface Area authorization requirements, we
determined that the Class E authorization requirement only pertains to
Class E surface areas for an airport, not the Class E extensions to
Class D, C and E airspaces.

This 2019 Power Point document entitled "Class E airspace", compiled by FAA Aviation Safety Inspector Kevin Morris for an FAA UAS (Unmanned Aircraft System) Symposium, contains graphics clearly indicating that no authorization is needed to operate an "unmanned aircraft" in surface-level Class E "extensions" (E3/E3a/E4 airspace), despite the language of FAR 107.41.

The FAA's LAANC system for authorizing flight of Small Unmanned Aircraft under FAR 107 (and also under the October 2018 44809 Recreational Exception for limited (hobby) recreational operations of unmanned aircraft, which uses the same phrasing as FAR 107.41) does not include any surface-level Class E "extension" airspace (E3/E3a/E4 airspace) in the "gridded" airspace where authorization may be requested, thus implying that no authorization is required to operate a Small Unmanned Aircraft System (sUAS) or hobby model airplane, drone, etc in this airspace under the terms of FAR 107 or the October 2018 Recreational Exception.

FAR 91.157(a) reads

"(a) Except as provided in appendix D, section 3, of this part,
special VFR operations may be conducted under the weather minimums and
requirements of this section, instead of those contained in § 91.155,
below 10,000 feet MSL within the airspace contained by the upward
extension of the lateral boundaries of the controlled airspace
designated to the surface for an airport."

This related ASE answer provided a (circa) 2010 response from the FAA ATO Western Service Center addressing the question of whether "Special VFR" operations may be conducted in surface-level Class E "extensions".  The FAA ATO Western Service Center's response contained the following passage:

Our opinion is that E4 airspace is not part of the airspace designated
as the surface area for an airport. The surface area for an airport is
D, C, or E2. Extensions are treated differently from surface areas
designated for an airport, ie there is no communication requirement.
In addition extensions, by definition in 7400.9, are not airspace
designated as the "surface area for an airport".

Yes, the regulations around the "extensions" are a real "train wreck" of ambiguity...

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How common are mayday calls?
How often does an aircraft make a mayday call?
I assume when confronted with an emergency on board, they will first deal with it, and not waste time contacting any one who would not be able to help anyway. And when they have time for such a call, there's no emergency anymore.
So, when does making a mayday call make sense?

Your assumption that ATC can't help anyways is incorrect. They can help in tons of ways: Clearing airspace for you, offloading navigational burden by providing radar vectors, assist in gathering information, alert rescue services, and the list goes on.

You have two questions "how common are mayday calls?" and "when does making a mayday call make sense?".  Should these be separate questions?

There are tons and tons of different types of emergencies. Some require dealing with right here, right now (for example, fire in the cockpit would qualify), while some are immediate threats to the safety of the flight but don't necessarily make the aircraft immediately unsafe (say, loss of all engine power; needs to be dealt with and may require e.g. clearing airspace for gliding, but you've got time to deal with it). Remember: Aviate, Navigate, Communicate. Keep the plane flying, keep it flying where you want it to go, and only with those taken care of do you talk to others about it.

Related

@MichaelKjörling And a great way to navigate in an emergency is to call ATC and get radar vectors and other instructions and have them find suitable diversion airports. So it's not clear cut as a catchy phrase makes it out to be.

@user71659 Absolutely! However, in an emergency situation, I think of the "navigate" in "aviate, navigate, communicate" more as in "keep the plane from colliding with features of the big lump below that is doing its best to collide with the plane at 10 m/s²". In other words, avoiding CFIT, and in VMC VFR avoiding other traffic. I'm not at all slighting the idea of reaching out for help in figuring out where to go and how (e.g. radar vectoring, flight following), or for that matter figuring out where you are. I'd do it in a heartbeat myself, if I needed it then. It sure beats the alternative.

From the point of view of a private pilot, the answer is that mayday calls are not terrifically common. I've certainly never heard one made in anger in a couple of hundred flying hours.
However your assumptions are correct in parts and wrong in others. First lets define what an emergency requiring a possible mayday call is, which answers your question about when it makes sense.

Mayday - A condition of being threatened by serious and/or imminent
  danger and of requiring immediate assistance.

That said, some of your assumption is correct:

I assume when confronted with an emergency on board, they will first deal with it

Absolutely! Pilots are taught to "Aviate, Navigate, Communicate" in that order. Any emergency while airborne requires you to keep the aircraft flying as a first priority. You'll notice Communicate is last after "knowing where you are and where you're going" (Navigate).

not waste time contacting any one who would not be able to help anyway

As pointed out in comments, this is an incorrect assumption. Once the pilot has some bandwidth to communicate there are numerable ways ATC could help in an emergency, such as (but not limited to):

Clearing surrounding airspace
Aiding with navigation, such as giving vectors to the nearest runway
Prioritizing landings
Helping you once you're (hopefully) safely on the ground - see below.

And when they have time for such a call, there's no emergency anymore.

Again, an incorrect assumption. Take the example of an engine failure. The aviate part calls for you to set up for maximum glide ratio, and do some checks to see if you can restart your engine. The navigate part could require you to find a suitable field to make an emergency landing. At this point (depending on your altitude) you might have a number of minutes before touchdown. Here's where you tell ATC the problem ("Mayday mayday mayday. G-ABCD, engine failure, 2 miles east of [city], 2,000 ft heading 180 degrees. emergency landing on field beside [big road]"). This has the benefit that they can communicate with emergency services - or at very least send someone out in a car to help you.
As you can see from the above example. The emergency still persists once the pilot has time to tell ATC about it.


text:
How does NOAA's P3 Orion safely navigate hurricanes?
I've been watching NOAA's P3 Orion fly though Hurricane Matthew a bit on Flight Radar 24.  Looks a bit like this for the curious:

source
It's the only plane actually in Hurricane Matthew.
What I'm curious about is how they get through there safely?  I know they have done it with prior hurricanes, and I assume they have some sort of weather radar on board (being a NOAA aircraft and all), but I also assume there is much more to why that P3 is able to make it through a Hurricane without breaking apart.
Anyone have some insights into what makes this possible?  I'm especially curious about what they do to avoid the worst pockets of the storm (assuming they do).

And for anyone curious about how it looks like when that plane hits the middle of the storm, here you go:

source
Clearly there's not that much weather to avoid in the eye of the hurricane, but getting through those walls has got be pretty difficult considering all the wind shear.

Have you ever watched this episode of Air Crash Investigation? It covers an incident of prop failure on the NOAA plane while flying indie hurricane Hugo

Don't they fly just fly over the eyewall rather than through it? They then drop radiosnodes into it to get the measurements they want.

@reirab Question 1 at this link (kinda wishing I'd found this article before posting!  Oh well, a chance for someone to get some points still.  The article doesn't go into deep detail anyway): http://www.hurricanehunters.com/faq.htm

The National Oceanic and Atmospheric Administration uses three aircraft for carrying out hurricane research- a Gulfstream IV SP and two Lockheed Martin WP-3D Orions, while the USAF 53rd WRS 'Hurricane Hunters' uses the WC-130J for this purpose. Of these only the latter ones are used for penetration purposes.
The Gulfstream is used to fly around and over the hurricane (the 45,000' ceiling helps). From noaa page:

The NOAA G-IV jet usually does NOT penetrate the hurricane eye, but is assigned to fly synoptic scale patterns AROUND the storm, deploying dropsondes along the way, in order to profile the environmental flow that is moving the hurricane.

The other two aircraft- the Orion and Super Hercules are not modified structure-wise (except for extra fuel tanks) for carrying out these missions. From the hurricane Hunters site:

These aircraft are not reinforced in any way in fact the only differences between a WC-130J and a C-130J is the addition of two external fuel tanks ..., a radiometer pod on the left wing and the two addition crew pallets in the cargo bay

The aircraft does have onboard weather radars, one of which is used exclusively for flight safety, with the others used for research:

Each WP-3D aircraft has three radars: nose, lower fuselage and tail. The nose radar (a solid-state C-band radar with a 5° circular beam) is used strictly for flight safety and is not recorded for research purposes.

The aircraft are also fitted with INE and GPS and also satellite communications for transmitting and receiving real time updates. During the flight, the flight crew are in constant communication with the flight director, and make adjustments according to the requirements:

During the most dynamic portion of the flight, Price is in constant communication with the Flight Director, who provides real-time flight guidance based on the radar picture.

As far as flying through storm is concerned, looks like they simply punch through it to get to the center- in the end, the aircraft could handle it. From USAF site:

... airplanes are built to go very fast through the air, and they don't care if the wind is 5 knots (nautical miles per hour) or 150 knots! .... Although there are usually some bumps on the way through, they are nothing that the airplane can't handle..

The NOAA officials say pretty much the same thing in this reddit AMA:

The WP-3D is built like a tough old pickup truck. It can handle a lot of abuse in the storm environment and come back and fly the next day.

Incidentally, according to noaa the aircraft crew are more concerned about the turbulence rather than the actual winds in the eye wall:

... hurricane's rainbands and the eyewall, which can get a bit turbulent. The eyewall is a donut-like ring of thunderstorms that surround the calm eye. The winds within the eyeall can reach as much as 200 mph [325 km/hr] at the flight level, but you can't feel these aboard the plane.
... the turbulent updrafts and downdrafts that one hits. Those flying in the plane definitely feel these wind currents. These vertical winds may reach up to 50 mph either up or down, but are actually much weaker in general than what one would encounter flying through a continental supercell thunderstorm.

Looks like they simply fly through it anyway. Basically, they 'crab' into the hurricane so that they reach the eye of the storm. From the Reddit AMA:

Depending on how strong the winds are you have to point the nose of the aircraft so that your track will lead you into the eye. The difference between heading and track is known as your drift angle. Sometimes you can have as much as 20-25 degrees of drift angle. We sometimes call this “crabbing” into the storm, where we are pointing the aircraft to the left or right to flight straight.

The image below shows the path taken by one of the aircraft during flight into Hurricane Hugo.

Zoomed-in radar image of Hugo's eye, taken during NOAA 42's flight. The flight path of NOAA 42 is shown as the white line (note the loops made within the blue area, the eye of the hurricane). The eyewall (red and pink areas on the radar image) contained violently strong winds. Image credit: wunderground.com; Image from hurricanscience.org

So, in some places you make it sound like they just "fly right in" and in others it sounds like they are using their nose radar to skirt the worst of it?  I'm a little confused as to which one is actually happening.

@JayCarr Kinda both- in the reddit AMA I was referring to, the director of hurricane division said "NOAA pilots and crew routinely fly in the high-wind environment of the hurricane and don't fear it tearing the plane apart. However, they are always monitoring for "hot spots" of severe weather and shear that they can often identify on radar and avoid if it's too severe.".

@aeroalias: Which is much easier for a hurricane than it would be for an extratropical storm of the same intensity, since tropical cyclones don't have the violent interactions between hot and cold air that are characteristic of all cold-core systems.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How much data do FDR and CVR generate on commercial jets?
I'm wondering about how much CVR and FDR data an A320 (for example) would produce and at what intervals.
I believe that there are 4 or 5 voice channel and several sensor data things. I'm trying to get some data on commercial jets. Is there any place I could get some data on this?

The requirements for Flight Data Recorders (FDRs) on airliners like the A320 is in 14 CFR 121. For a good summary of the requirements for flight recorders in various types of aircraft, see the NTSB FDR Handbook.
Depending on the certification date of the aircraft (14 CFR 121.343), the FDR must record between 6 and 17 parameters. Since engine parameters are included, this could be up to 23 different parameters on 4-engine aircraft. Newer Digital FDRs (DFDRs) must record at least 88 items (14 CFR 121.344). Some of these parameters are conditional, and some require multiple parameters, so the total will probably be more than 88 parameters. The NTSB report on the US Airways 1549 accident notes that the FDR recorded 178 parameters during the flight.
According to this page, tape-based DFDRs can record at 64 12-bit data words per second. Newer DFDRs using solid state recording can store up to 256 12-bit data words per second. This 256 words per second is also specified in the information on this FDR. It says it can record >100 hours at 64 words/second, which translates to about 35 MB total. The parameters are per DO-160C standard, which you have to pay to access.
Accident reports will generally include readouts from relevant parameters, to give an idea of the items that are recorded. There is a table here showing some parameters, the measurement range, and recording intervals. The interval is anywhere from 0.125 seconds to 4 seconds depending on the parameter.
Aircraft may also have a Quick Access Recorder (QAR), which records many parameters (over 2000). However, aircraft are not required to have one and the QAR is not required to survive an accident. Airlines use them for data to improve operations, and they can also be used in less severe crashes for analysis.

thank you! very interesting 0.125 is along the numbers of what I heard, where did you come to that number though? but 3.1 kbit sounds a bit low?i heard something more along the lines of 5-6 how is that possible? apparently the DFDAU may generate much more data right? also how can i see how much the CVR would generate?
(I trying to accurately simulate data transfers of fdr + and excluding cvr, but i don't have anything quotable yet)

The 0.125 comes from the document linked in that section, there is a table with parameters and their intervals. I'll try to address you other questions in an edit later.

perfect thank you i'll need to read it properly! thanks a bunch

You can access the Honeywell website and download and read the manuals, brochures, drawings and schematics about connections of voice and data recorders. Honeywell is the largest manufacturer of black boxes for commercial, civil and military aviation.
Honeywell was among those who provided the black boxes for the A320 that crashed in the French Alps. There are many models and types of Flight Data Recorders (FDR) and Cockpit Voice Recorders (CVR), and they also record the status of other devices. There are many types of FDR's and CVR's whose characteristics depend on the type of aircraft and customer specifications.

Hello Luiz, and welcome at Aviation.SE. Please try to answer the question by including the information you can retrieve via the provided link. It is better to have the basic information here on the site and then have the link as reference. This is also helps in case the link breaks.  BTW, I can't find any accessible manual and brochures there at first glance.

From Wikipedia: Flight recorder
An FAA-standard flight data recorder will record a minimum of 88 parameters, sampled several times per second.  An FAA-standard cockpit voice recorder will record four channels of audio.

there can be more parameters recorded but those are minima


text:
Can a normal jet bridge reach an upper deck?
We have planes with an upper deck since the time the B747 was born. Now we have the A380. I wonder if a normal jet bridge can reach the upper deck of both planes? The scenario in my mind is if an A380 has to divert somewhere that does not normally serve the A380, can a normal facility be used? Or does a passenger have to walk down the internal stair to exit via the lower deck?
Related news

here are some details about the doors on the 747 and A380; not an answer, of course.

The A-380 is such a different beast that they basically have their standard divert airfields, and anything not on the list is a huge big deal... as in, the taxiways may not be stressed or have wingspan clearance for them. So getting a jetbridge to the upper deck is probably far down the list of concerns in that situation. If you must deplane, maybe just getting everybody off thru the lower deck is enough.

Jet bridge capability varies by design.  Some airports are equipped for this while others are not.  A diversion to an airport not listed in the airline's procedures would be considered only in the most time-critical emergency.


text:
What are the pros and cons of having a side-stick versus a centered control stick in a fighter aircraft?
The Eurofighter Typhoon features a centered control stick:

While for example in the F-16 the stick is on the right side panel:

I find the latter configuration much more natural/ergonomical. Especially since the concept of HOTAS (Hands On Throttle-And-Stick) implies that the pilot has his hands on the same control element most of the time.
I've heard of one reasone for having a center stick is to allow for ambidextrous operation (operations with both hands, alternatively).
But this seems to be counter-intuitive with HOTAS, especially since the throttle controls are still on the left side only.
I find it difficult to image an ergonomical position for the pilot while holding a center-stick and a left hand throttle control.
So what are the reasons for a center stick in the Typhoon?
Any experiences of pilots having flown both types of configurations?

If you look at the joystick handle for the Typhoon, it is not left/right handed, it is right handed only. I doubt they have interchangeable handles for pilots. It makes sense to be right handed since the throttle is only left handed in that configuration as well.

Related Why do most fighter craft have a center stick?

Thanks. I have read the answer from the presumed dup thread. The phrase given by Eurofighter "[...] there is no reason to have anything other than a center stick" (in sufficiently large cockpits) doesnt sound well argued to me. I do concede that center sticks are the historical default, but it seems to me that most modern designs (F-35, F-22, Rafale) opt for a side stick. @ymb1, I dont like your title edit, I gave Typhoon merely as an example of a modern design with center stick. But the general question is about why center sticks would still be useful/preferred in modern fly-by-wire designs.

Center mounted sticks are useful for maintaining positive control of the aircraft while operation some cockpit system on the right consoles and flying with your left hand.  It’s also useful in an emergency, say if your right arm was injured by shrapnel, etc and cannot actuate the stick effectively, requiring you to fly with your left hand.
Side sticks do have the advantage of less cockpit clutter.  The stick is mounted off to the right and doesn't directly block critical instruments from the pilot's view or have its range of motion restricted by flight gear, kneeboards, etc.
As far as size and weight are concerned, both center mounted and side sticks are pretty much the same in a fly-by-wire aircraft - just a 4-way transducer LRU with a handgrip attached to it.  In a/c with conventional control systems the center stick was a necessity as it acted as a lever arm allowing the pilot to overcome aerodynamic forces on the control surfaces with muscle power alone and one could force a maneuver using both hands.  In the age of hydraulic flight controls and fly-by-wire, this is irrelevant.
As to ergonomics, it's fairly comfortable to fly a center stick as your wrists will naturally rest on your thighs when seated and your hands naturally float to that position.  Side sticks are also comfortable but require an armrest to operate effectively, particularly when pulling Gs.

But if your left arm was injured, you can't handle the throttle either. Those arguments in favor of a central stick are all asking for a central throttle as well.

In fact you can use one hand for the throttle and control the stick with your legs. Yes, pilots in the F-18 have a center stick and often have to control it with their legs, freeing up the throttle for another hand and the injured arm/hand can rest.

Besides the issues already covered, it appears to me that older fighters would prefer a center stick so the pilot can switch hands if he needs to see behind the cockpit in either direction.
The newer USA F22 & F35 use a helmet with virtual vision and supposedly the pilots don't need to twist their heads to see behind them - though some pilots have challenged the safety and effectiveness of this feature.

source

picture updated source
This is a side stick F16. Note the ability of the pilot to brace with his free hand looking to his right but unable to do the same looking left because his right hand must stay on the side stick. A center stick would have allowed a free hand in either direction.

Could it be that the F-16 in the lower picture was re-fitted with the cockpit and wing of a BAe Hawk?

Lmao @PeterKämpf you're right that's pretty funny!

corrected the picture :)

As already mentioned in the question, I don't believe this to be a valid reason for a center stick.
First, when rapidly grabbing the stick with the other hand, the pilot would probably make unwanted control inputs.
Second, even a centered stick has a distinctive right-hand ergonomic layout, which would feel awkward at best when operated with the left hand or totally inoperable at worst. (Buttons are at the wrong places with respect to thumb, index finger etc.)
Third, the pilot would want to hold his other hand on the throttle control, especially in an emergency situation like a dogfight.


text:
How to calculate the shear force, and the bending and torsion moments on a wing?
I want to calculate the loads (shear force, bending and torsion moments). Assuming I have the force distribution along all the surfaces of the aircraft, my starting point is to consider the wing (and other surfaces whose loads I want to calculate) to behave like a cantilever. So, I've got these formulas:
$$
S_z =
\int_z^{b/2}
F
\;dy
$$
$$
M =
\int_z^{b/2}
S_z
\;dy
$$
Where
Sz = shear force in point z;
Mz = Bending Moment in point z;
F = Lift Distribution;
b = Wingspan;
and the coordinate system is as follows:

Are these formulas correct, and how can I calculate the torsion moment?

Your wingspan coordinate is y, therefore the integration should run from 0 to b/2. The z coordinate in your sketch is confusing - should that not be the force direction? Shear is in z and bending around x, so it should be $S_z$ and $M_x$. If you add $M_y$ you will also have a term for torsion. And there is no point z, only one like (x=0; y=0; z=0) or so.

@PeterKämpf if you look z in this case is not an axis, but a generic value along y. the formulas are to compute S and M at z.

@Federico: In the sketch, z looks like a length along y. Then it is a point. Normally, it should be the third coordinate, which is missing. A point along y should be y=something, not z. Clarity in asking often gives you the answer already.

@PeterKämpf "In the sketch, z looks like a length along y." exactly my point. Also, in the question "Sz = shear force in point z". So yes, it is a point, not a coordinate as you first said. Sure, usually it would be, but not here and is quite clear.

"z" is a point along the y-axis. Sz, for example, means the shear force applied to point z of the 'beam' that supports the structure of the wing


text:
What are good ways to gain experience and flying hours?
As a pilot who has just graduated, what are the ways to gain experience and flight hours?
The first thing airline look at is your flight hours, they usually require 1200 hours.
Is there any chance for a fresh graduated pilot to get hired in an airline with only 250 hours of flying?
I'm graduated in the Philippines.

Please specify the country you are asking about. Some of the hour limits are imposed by governing bodies and may change from country to country.

@Dave edited thanks.

Most people I know got their hours working as a flight instructor. You could also try to talk friends into going on trips with you. They split the cost with you, and everyone has a good time!

Similar or duplicate: What can a new commercial pilot do to build flight time? Although that question is tagged with FAA, but the answers don't just refer to a particular demographic.

There are a few ways to do it.
As has been mentioned many people here in the US are flight instructors (my instructor is building hours to go commercial eventually).
As has also been mentioned you could build hours taking trips with friends and splitting the cost but even split 3 or 4 ways this can get expensive fast.
You could do things like tow gliders or banners if they have that kind of advertising near you. It's not glorious and I can't imagine it's that fun as far as flying goes but it will build you hours.
I'm not sure how to get into flying planes for sky diving tours but that is another option to just build hours.
Again your hours may be an issue but you could look into ferrying planes for people. This can be tough if you don't have a lot of experience in different planes.
These are just a few things that come to mind. There may be varying laws in your area so its worth checking up on that before trying any of these things.

appreciate your options dave.

You can instruct or split time with friends but I doubt that you want to do that.Working as a First Officer for a cargo airline is a good way to gain hours. These airlines can be shoddy operations so be careful.  You will not make much money, maybe none at all, but you will get hours and get great experience.  Most cargo airlines fly old, trashy planes with minimal equipment and usually fly into smaller airports.  Weather is a secondary concern in many cases.  In fact, a common joke is: "Why check the weather?  We're going anyway."  The experience you'll gain from flying old, obsolete equipment into small fields and through terrible weather is extremely valuable and will make you a better pilot!  You will learn more in 250 hours of cargo flying in second-rate equipment than you will just about anywhere else.  I cannot recommend it highly enough!
Now, the job I've described is difficult to find.  It's a niche that hundreds just like you are willing to pay for (literally pay for a job as a First Officer).  You may have to offer your services for free in exchange for the training the airline is required to give you to make you a crew member.  This is not cheap as it requires the company to burn hundreds of gallons of fuel to do your flight training!  Your existence becomes one of a pilot for the company...you will never drink, you'll live your life within one hour of the airport, and you will never take a vacation.  For as long as you're a FO, your only purpose in life is to gain hours, nothing (and I mean nothing) else.  I cannot stress this enough.  Most small companies are doing you a favor by even considering you for an FO position.It is important to realize that simply because a company makes you a FO does not mean you can log flight time!  You must be flying a plane that requires an FO and the kind of flying you're doing must require a FO.  For example, a properly rated pilot can fly a Metroliner as a single pilot as long as he's flying cargo.  As soon as a passenger* boards the plane, that single-pilot must either have an autopilot or a First Officer.  This is where you come in. A lot of these older planes have had their autopilots removed by the cargo companies!  They cost too much to maintain and each pilot must be trained on the operation of each autopilot the company uses.  It's cheaper to remove them than it is to conduct the training and maintain the equipment.
*A passenger is anyone who is not a required crew member.  You would be considered a passenger if you flew in the right seat without being trained a First Officer.  Sometimes a company employee can ride along with a single pilot under circumstances.  You cannot exploit this loophole to gain experience legally, though many people do log time and "build hours" this way.  The vast majority are never caught and most are told it's legal by companies selling time to low time pilots.  The FAA does not seem to enforce this at all.


text:
What is transmitting this radio signal @~110.515MHz and for what purpose?
I was scanning the local aviation radio frequencies, and came across an odd signal (listen to a recording here).
It's at around 110.515MHz, and it seems strong within a 30 mile radius of Shropshire, UK (haven't tried tuning in further afield).
Not sure if it's relevant, but there are a couple of RAF bases nearby (RAF Shawbury and RAF Cosford).
I presume it's a navigation aid, but couldn't find anything listed on that frequency.
I was hoping someone would recognise the sound and be able to tell me what equipment is transmitting it (e.g. NDB).

That frequency band is typically used for VOR (VHF Omni Directonal Range) or LOCalizer (part of the Instrument Landing System, ILS) but the frequencies are rounded to 0.05MHz. I did a quick check and I didn't find any systems near your place on that frequency (110.5 nor 110.55)

Telford Electronics is nearby, perhaps they have something leaking that signal?

Thanks guys. Do you know anywhere I can listen to VOR and LOC signals to compare them?

I might have a go at triangulating the source; need to figure out how to build a directional FM antenna... I'm sure Google can help with that!

It's a clearly modulated signal in your recording. Can you identify the frequencies of the modulation? There must be software to do that. If you know the modulation frequencies that will help.

I'm at loss to what signal it is @mins, it may be interference between two channels or something military. The 150Hz sidebands are interesting because 150 Hz (and 90Hz) are used in ILS.

Thanks for your interest and help guys.
I've just sent a tweet to the Shawbury RAF Station Commander. Perhaps they'll know - it seems likely it's originating from there, and if not, they'll probably know what it it.
Whether or not they'll have time to spend answering the question is another matter...
Failing that, I'll try sampling transmissions from adjacent frequencies to see if there are two distinct signals colliding.

The signal spans 110.510-110.535MHz, but seems clearest at 110.515.

There's another intermittent transmission at 110.55, but the timing is different; far less frequent, and sounds completely different. Don't think it's related.

Shawbury ILS is on 108.7.
110.5 has Stansted, Bournemouth and Scamption ILSs. 110.55 used to be Filton.

I've not abandoned this, just haven't had the time to build a directional antenna yet. I'd be interested to hear from anyone around the UK who can check this frequency themselves and advise if they're receiving the same signal.

Well, the SDR dongle paid off - mystery solved.
It turns out, the signal was actually at 153.2MHz, but was somehow breaking through into 110.515MHz on my handheld scanner.
The signal originates from a high power pager transmitter using the FLEX protocol. As this is plain text, I decoded some of it using an excellent open source application called PDW, and have listed it below for reference and general interest (sensitive information has been redacted!).
  0074162  23:12:31 30-06-15 FLEX-A    ALPHA   3200   31:Jun 30 23:11 Trim Line 2 L359 Error Check 01 Override 010312 30-JUN-2015 23:10:49
  0000002  23:12:56 30-06-15 FLEX-A    ALPHA   3200   THIS IS A TEST PERIODIC PAGE SEQUENTIAL NUMBER  0069
  0121518  23:12:59 30-06-15 FLEX-A    StNUM   3200   31948
  1734139  23:13:01 30-06-15 FLEX-A    ALPHA   3200   61:Jun 30 23:12 Term B  Page-fail test
  1756286  23:13:24 30-06-15 FLEX-A    ALPHA   3200   PIN 6840 PLS CALL DSCC ON 08457 500***
  0118459  23:13:46 30-06-15 FLEX-A    ALPHA   3200   20150630 23:13 boc1web02.servstream.com: conn CRITICAL ALERT
  0000002  23:14:03 30-06-15 FLEX-A    ALPHA   3200   THIS IS A TEST PERIODIC PAGE SEQUENTIAL NUMBER  0070
  1734139  23:14:09 30-06-15 FLEX-A    ALPHA   3200   62:Jun 30 23:13 Term B  Page-fail test
  0076963  23:14:29 30-06-15 FLEX-A    ALPHA   3200   55:Jun 30 23:13 23.13hrs Zone 14 L550 down 15 Mins maint in attendance FROM: GB50-AFENNEL3
  0074162  23:14:46 30-06-15 FLEX-A    ALPHA   3200   32:Jun 30 23:13 Trim Line 2 L359 Error Check 01 Override 010312 30-JUN-2015 23:12:42
  0074179  23:14:48 30-06-15 FLEX-A    ALPHA   3200   19:Jun 30 23:13 Z2A LH Stn 200  Main Call 30-JUN-2015 23:13:22
  0074194  23:14:50 30-06-15 FLEX-A    ALPHA   3200   56:Jun 30 23:13 23.13hrs Zone 14 L550 down 15 Mins maint in attendance FROM: GB50-AFENNEL3 FROM: GB50-AFENNEL3
  0107291  23:14:50 30-06-15 FLEX-A    StNUM   3200   2422085
  0074076  23:14:50 30-06-15 FLEX-A    ALPHA   3200   60:Jun 30 23:13 Fac 1670 More than 20 I/P on conv 30-JUN-2015 23:11:30
  0086317  23:14:52 30-06-15 FLEX-A    ALPHA   3200   36:Jun 30 23:13 Dodo Panel 23 Entry Movement Alarm 000065 30-JUN-2015 23:12:03
  0000002  23:14:56 30-06-15 FLEX-A    ALPHA   3200   THIS IS A TEST PERIODIC PAGE SEQUENTIAL NUMBER  0071
  0067432  23:14:59 30-06-15 FLEX-A    ALPHA   3200   71:Jun 30 23:14 Water Test WATER TEST SUMP LEVEL HIGH 001215 30-JUN-2015 23:14:46
  1754937  23:15:16 30-06-15 FLEX-A    ALPHA   3200   'Adv' 7440298 30/06/2015 23:08:33 tight chest, struggling to breathe, EMAS ETA 11 mn, Priority RED2 Age 59 Incident area - KETTERING ** ****** ** NN16 ***
  0067432  23:15:22 30-06-15 FLEX-A    ALPHA   3200   72:Jun 30 23:14 Skid RETURN PROBLEM CHECK SKID RETURN Tested o.k. 30-JUN-2015 23:12:25
  1734139  23:15:24 30-06-15 FLEX-A    ALPHA   3200   63:Jun 30 23:14 Term B  Page-fail test
  0086317  23:15:44 30-06-15 FLEX-A    ALPHA   3200   39:Jun 30 23:14 Dodo Panel 6 P&F Emergency Stop relay 125KN1 - 400301.08 30-JUN-2015 23:13:32
  1734136  23:15:46 30-06-15 FLEX-A    ALPHA   3200   19:Jun 30 23:14 Term A  Page-fail test
  0067154  23:15:50 30-06-15 FLEX-A    ALPHA   3200   Fr:nocteam Su:Escalate PQV-73575-125 Tx:Auto escalation of ticket (3 hour rule) Ticket: PQV-73575-125 Queue: VelociX Date raised: 2015-06-30 20:11:27 Subject: ANTEL New asset request
  0117556  23:15:54 30-06-15 FLEX-A    ALPHA   3200   PLS CALL DUTY OFFICE
  0000002  23:16:03 30-06-15 FLEX-A    ALPHA   3200   THIS IS A TEST PERIODIC PAGE SEQUENTIAL NUMBER  0072
  0111087  23:16:07 30-06-15 FLEX-A    StNUM   3200   71301
  0118459  23:16:16 30-06-15 FLEX-A    ALPHA   3200   20150630 23:15 boc1backup.siops.net: msgs CRITICAL ALERT
  1734139  23:16:31 30-06-15 FLEX-A    ALPHA   3200   64:Jun 30 23:15 Term B  Page-fail test
  0074208  23:16:37 30-06-15 FLEX-A    ALPHA   3200   69:Jun 30 23:15 Warning : BODY DELIVERY STN 1 OVERCYCLE * BD SKID BD SKID (52)
  1734136  23:16:54 30-06-15 FLEX-A    ALPHA   3200   20:Jun 30 23:16 Term A  Page-fail test
  0074221  23:16:54 30-06-15 FLEX-A    ALPHA   3200   09:Jun 30 23:15 Warning : BODY DELIVERY STN 1 OVERCYCLE * BD SKID BD SKID (53)
  0120075  23:16:56 30-06-15 FLEX-A    ALPHA   3200   PLS CALL 12F ON 42848 2ND CALL
  1734139  23:17:39 30-06-15 FLEX-A    ALPHA   3200   65:Jun 30 23:16 Term B  Page-fail test
  1756806  23:17:41 30-06-15 FLEX-A    ALPHA   3200   PLS CALL ***** ***** - ADDENBROOKES ON 01223 257 ***
  0121619  23:17:42 30-06-15 FLEX-A    ALPHA   3200   P2 TS 3170
  0074162  23:17:46 30-06-15 FLEX-A    ALPHA   3200   34:Jun 30 23:16 Trim Line 2 L359 Error Check 01 Override 010312 30-JUN-2015 23:15:30
  1728604  23:18:05 30-06-15 FLEX-A    ALPHA   3200   41:Jun 30 23:17 ****** ******** 07711 239 ***
  0067432  23:18:07 30-06-15 FLEX-A    ALPHA   3200   73:Jun 30 23:17 Conv 11 Conv 1 Starved Load stn Blocked 30-JUN-2015 23:14:55
  0090980  23:18:07 30-06-15 FLEX-A    ALPHA   3200   30/06/2015 23:15:02 INC 14517765 ETFR Countess of Chester Hospital Chester Cheshire -, THE COUNTESS OF CHESTER HEALTH PARK, CHESTER, CH2 *** Male 25Y ProQA Overrid
  0090980  23:18:09 30-06-15 FLEX-A    ALPHA   3201   [Continued message - Fragment #2]den - Call Escalated GRD 340129 368274
  0067432  23:18:09 30-06-15 FLEX-A    ALPHA   3200   74:Jun 30 23:17 Conv 11 Conv 1 Starved Load stn Blocked 30-JUN-2015 23:14:55
  0067432  23:18:11 30-06-15 FLEX-A    ALPHA   3200   75:Jun 30 23:17 Water Test BOOTH 2 LOW / HI WATER PRES30100230 KU-.2N1u013 (?E4
  0118459  23:18:11 30-06-15 FLEX-A    ALPHA   3200   30 23:17]X[??Xns01.siops.net: dnPyt7xyICAL ALERT
  0114910  23:18:13 30-06-15 FLEX-A    ALPHA   3200   40:Jun 30 23:17 PLS CALL LEAH ON EXT 31505
  0119227  23:18:16 30-06-15 FLEX-A    ALPHA   3200   42:Jun 30 23:17 PLS CALL DUTY NURSE 020 7561 ****
  0120151  23:18:27 30-06-15 FLEX-A    ALPHA   3200   PLS COME TO CAVENDISH UNIT
  0118459  23:18:46 30-06-15 FLEX-A    ALPHA   3200   20150633 27z1b"bocm$n:th4Cp
  1743989  23:18:46 30-06-15 FLEX-A    ALPHA   3201   [Continued message - Fragment #2]
                                                          WN i$*CHER 01226 872 199 REajlFE AT POST OFFICE WONPi OCK AND IS WIDE OPEN*?f
  1756806  23:18:48 30-06-15 FLEX-A    ALPHA   3200   PLS CALL ***** ***** - ADDENBROOKES ON 01223 257 ***
  1734139  23:18:54 30-06-15 FLEX-A    ALPHA   3200   66:Jun 30 23:17 Term B  Page-fail test
  0000002  23:18:56 30-06-15 FLEX-A    ALPHA   3200   THIS IS A TEST PERIODIC PAGE SEQUENTIAL NUMBER  0075
  1734136  23:19:16 30-06-15 FLEX-A    ALPHA   3200   22:Jun 30 23:18 Term A  Page-fail test
  0067432  23:19:22 30-06-15 FLEX-A    ALPHA   3200   76:Jun 30 23:18 Conv 11 Conv 1 Starved Load stn Blocked 30-JUN-2015 23:16:09
  0067432  23:19:24 30-06-15 FLEX-A    ALPHA   3200   77:Jun 30 23:18 Conv 11 Conv 1 Starved Load stn Blocked 30-JUN-2015 23:16:09
  0076517  23:19:26 30-06-15 FLEX-A    ALPHA   3200   38:Jun 30 23:18 Conv 21 Check Zone Start Pulse Count 30-JUN-2015 23:19:15
  0114375  23:19:26 30-06-15 FLEX-A    ALPHA   3200   30:Jun 30 23:18 Conv 21 Check Zone Start Pulse Count 30-JUN-2015 23:19:15
  0076956  23:19:27 30-06-15 FLEX-A    ALPHA   3200   97:Jun 30 23:18 Conv 21 Check Zone Start Pulse Count 30-JUN-2015 23:19:15
  1734139  23:20:01 30-06-15 FLEX-A    ALPHA   3200   67:Jun 30 23:19 Term B  Page-fail test
  0000002  23:20:03 30-06-15 FLEX-A    ALPHA   3200   THIS IS A TEST PERIODIC PAGE SEQUENTIAL NUMBER  0076
  0074162  23:20:09 30-06-15 FLEX-A    ALPHA   3200   36:Jun 30 23:19 Trim Line 2 L359 Error Check 01 Override 010312 30-JUN-2015 23:18:09
  0114910  23:20:13 30-06-15 FLEX-A    ALPHA   3200   41:Jun 30 23:19 PLS CALL **** ****** ON EXT 34335
  1734136  23:20:31 30-06-15 FLEX-A    ALPHA   3200   23:Jun 30 23:19 Term A  Page-fail test
  0102150  23:20:33 30-06-15 FLEX-A    StNUM   3200   0778
  0000002  23:20:56 30-06-15 FLEX-A    ALPHA   3200   THIS IS A TEST PERIODIC PAGE SEQUENTIAL NUMBER  0077
  1734139  23:21:09 30-06-15 FLEX-A    ALPHA   3200   68:Jun 30 23:20 Term B  Page-fail test
  0076517  23:21:14 30-06-15 FLEX-A    ALPHA   3200   39:Jun 30 23:20 Conv 21 Check Zone Start Pulse Count 30-JUN-2015 23:21:02
  0119626  23:21:18 30-06-15 FLEX-A    ALPHA   3200   34:Jun 30 23:20 Conv 21 Check Zone Start Pulse Count 30-JUN-2015 23:21:02
  0102150  23:21:18 30-06-15 FLEX-A    StNUM   3200   0775899******
  0076956  23:21:20 30-06-15 FLEX-A    ALPHA   3200   98:Jun 30 23:20 Conv 21 Check Zone Start Pulse Count 30-JUN-2015 23:21:02
  0200905  23:22:34 30-06-15 POCSAG-3  ALPHA   1200   23:22-98 30/06/2015 23:20:18 INC 14517787 31C02 ************, ELLESMERE PORT, CH65 *** Male 64 Years M PASSING OUT GRD
                                                      340506 375692
  0334410  23:23:50 30-06-15 POCSAG-3  ALPHA    512   23:22-41 C2 Incident Allocated, Locn: *****, GREENACRES CARE CENTRE, TEARN ROAD, PL35JF, , AZ:, CAD:300615005110, ChComp:
  1508907  23:23:51 30-06-15 POCSAG-4  ALPHA    512   CH3A 512
  0273040  23:24:04 30-06-15 POCSAG-4  ALPHA   1200   30/06/2015 CH3A
  0269168  23:24:20 30-06-15 POCSAG-3  ALPHA   1200   23:24-10 30/06/2015 23:22:15 INC 14517792 10D02 ***********, NEWBOLD ROCHDALE ROCHDALE, OL16 *** Female 24 Years
                                                      MIGRAINE - FEELS SICK GRD 390789 412576

Also, thanks again to everyone for their input.

Thank you for posting the follow up! Probably your scanner uses an intermediate frequency which caught the interference. Amazing that you found the origin and the protocol used.

Good work impressive

Impressive job! What SDR dongle are you using?

I picked up a Newsky RTL2832U + R820T2 RTL-SDR on eBay for $24 delivered.
I used SDR# on Windows and Dennis Mantz's RF Analyzer on Android.

If your frequency is accurate then it uses 25 khz spacing. VHF channels can be spaced at 100khz, 50 khz, 25 khz, 12.5 or 8.333 - hence the more decimal places on the dial.
I think you might have picked up a marker beacon based on someone elses analysis. Basically there are three tones at 1020 hz / 1300 hz and 3khz that tell a pilot how far he is from the runway.
I don't think you would get the signal from 30 miles though, but you never know.
Also the 150hz tone can be from the localizer - which will definitely be valid over 30 miles. there are two tones - one at 90 hz and the other at 150 hz.
Obviously these are modulated on the carrier frequency, and these are part of the ILS system.
I have a feeling you don't have the exact frequency but see if it is stronger
at 110.55, if it is then this is the localizer frequency.
The 100khz digit is odd for localizer frequencies.
Hope this helps

Thanks for the info.
I've just purchased an SDR dongle and will use the waterfall view to see if I can identify the full frequency range on which the signal is transmitted.


text:
Sidestick safety concern
I read about several aircraft crashes throughout aviation history and the investigations on wikipedia and also checked out some episodes of the documentary "Air Crash Investigation".
While of course I can only make conclusions of what I read, hear and see it appears, that problems related to communication are one typical reason to contribute to such disasters.
Something that attracted my attention is that the sidesticks used in the aircrafts of Airbus seem to be involved in not less than three crashes including Air France Flight 447.
Though there is the general distinction pilot flying (PF) and pilot not flying (PNF) failures, malfunctions and the triggered warnings tend to create a situation of stress and strain in the cockpit as comprehensible. Confusion comes up not seldom in such situations.
My point finally is, that

Sidesticks are smaller than yokes. To apply a control input one only needs to turn one's wrist while a yoke requires you to use both of your arms to make the big aircraft turn. I wonder if the inhibition threshold therefore is somehow lower to make extreme, exaggerated inputs in case of a sidestick?
Secondly, and this is the major question, as it appears, the sidesticks make it much harder, to be aware of the currently applied control input (especially) for the other pilot. While the yokes of both pilots are physically connected and both pilots have direct feedback of the currents state at any given time, the sidesticks

give no feedback to the other sidestick
are smaller, which makes it harder to see the current state their in already by the size alone
are more distant than yokes making it again harder to see for the other pilot, as this A380 cockpit shot shows

Question:

How is the general assessment of those sidesticks concerning safety?
Is there any feedback to the pilots which stick is giving what input?
Has there been any development in improving this situation?
What are the accidents/incidents sidesticks more or less contributed to confusion/lack of information?

Related question

Yokes don't require two arms to be moved (see https://www.youtube.com/watch?v=Xmo6-KxwOWw)

It could be a bit broad, and asks for opinions at the same time...

Other related

I've changed 'security' to 'safety' since it seems the author is looking for unintentional events involving the sidestick. Feel free to roll back if you we're looking for malicious intent

it also happens that side-sticks are found on the fly-by-wire Airbus. you'd be hard pressed to factor one or the other out.

Not only do yokes not require two hands, it's actually quite uncommon to use two hands on a yoke. My flight instructor always objected immediately if I ever put my right hand on the yoke. - haha

Yokes need not be connected on FBW aircraft. Boeing does have the yokes connected, but that was a design choice; they didn't have to. Sidesticks can provide feedback; Airbus doesn't, but you can.

Sidesticks are smaller than yokes. To apply a control input one only needs to turn one's wrist while a yoke requires you to use both of your arms to make the big aircraft turn.

Side-sticks are used together with control laws. In an Airbus Normal Law (and Alternate Law which differs only by not providing the flight envelope protections), the system automatically trims for 1 G wing loading (which equals constant flight path angle) and zero roll rate and the side-stick deflection commands wing loading in pitch and roll rate in roll. The springs are sufficient to provide all feedback there is to provide as the deflection and the force both correspond to the command given.
Due to the way side-sticks work, extended deflection is rarely necessary, nor are very fine adjustments normally needed to stabilize the plane on desired flight path, because the computer handles that.

Secondly, and this is the major question, as it appears, the sidesticks make it much harder, to be aware of the currently applied control input (especially) for the other pilot.

Feedback, on any kind of control, is provided by position and force. The other pilot can only feel the position. This allows them to notice that the other pilot pulled up, but not whether it is dangerously close to stall, because the stick position is biased by aircraft balance and, if horizontal stabilizer is used for trim (which all airliners do), also by trim. So the information it provides is rather limited.
On Airbus the side-sticks are not connected, so even this limited information is not available. But they have an advantage too. If the pilot flying is incapacitated or confused, the pilot monitoring can push a “control priority” button on the side-stick and the computer then only responds to their side-stick, so they don't have to fight with the other pilot on the controls.

How is the general assessment of those sidesticks concerning safety?

I've not seen any specific study. But they were approved and I am not aware of any accident on Airbus where similar accident wouldn't have happened with other type with traditional control column.

Is there any feedback to the pilots which stick is giving what input?

If both side-sticks are giving input, there is aural and visual warning “dual input”. If one pilot presses the “control priority” button, there is an announcement “control priority left/right” and visual indication. There is no direct indication of what the command is, but the pilots are looking for what the plane is doing anyway and they can usually judge from that. There is also indicator of control surface positions.

Has there been any development in improving this situation?

I am not aware of any aviation authority thinking there is a problem to fix. Manufacturers are coming up with new schemes they consider good, but that may be as much marketing as genuine improvement.

What are the accidents/incidents sidesticks more or less contributed to confusion/lack of information?

I can't think of any where it could be said the situation would have been significantly better if the controls were linked. If both pilots are confused, the connection would not help much and if only one is confused, the other can use the control priority to take over.
Even AF447, where some dual input was involved, is not really unique. There have been several crashes where pilots didn't realize a stall and didn't attempt recovery all the way from cruise level down to the ground (the most recent one) and all the others happened in planes with mechanically connected control column.

In your answer you mention one pilot can push a button to gain full control of the sidestick regardless of what the other pilot is doing. What happens if both pilots attempt to push this button?

@Ksery, IIRC it cancels out. This is not a defense against malicious pilot—malicious pilot has many ways to screw things. It is defense against pilot losing consciousness and leaning against the stick, against pilot who is too confused to respond to verbal instructions and against the stick getting stuck.

Regarding question 2:
There is no tactile or visual feedback (i.e. no sidestick movement when autopilot engaged). There may be visual cues on Airbus aircraft from the Side Stick Priority lights in front of each pilot on the glareshield. There is also an aural warning if sidestick priority is taken.
Regarding question 3:
The next generation of sidestick controls for fly-by-wire commercial aircraft are called Active Sidesticks and will provide visual and tactile feedback. They can already be found on the Gulfstream G500 and G600 aircraft.
This article from Aviation Week & Space Technology provides details.

This kind-of answers a very small part of the question, and ignores most of it - how safe are current sidesticks?

Well, I answered question 3 since that's where I was best able to contribute. If you want to add to my answer, go ahead. Personally I feel that active sidesticks will be a positive contribution to safety.

The "next generation" is not really a next generation. It uses the feedback technology that Boering uses on control columns with side-stick. Airbus doesn't, and probably never will, because it makes no sense in Airbus. Because the springs provide all feedback there is to provide in normal and alternate laws.

Murphy has no place in an Airbus, then?


text:
Why isn't it possible to locate the rudder in front of an airplane's center of gravity?
Why isn't it possible to locate the rudder in front of an airplane's center of gravity?
Specifically how does this relate to the stability derivative?

I'm not convinced this is a direct duplicate - the rudder doesn't necessarily have to be attached to the vertical stabilizer. The linked answer is PART of the answer to this question, but not an entire answer in itself.

The Rutan Defiant push-pull canard has a ventral, starboard offset, forward mounted rudder. And, adding support to @JonStory 's comment, it is separate from the fins, which are mounted on the wingtips.

Effect on Aerodynamic Coefficients
It is possible to locate a vertical fin, as well as a control surface, ahead of the center of gravity.  $c_{n_r}$ (yaw-induced yawing moment or yaw damping) will not likely change much, all other things being equal. $c_{n_\beta}$ (sideslip-induced yawing moment or directional stability), on the other hand, will be reduced, perhaps becoming negative. Any sideslip will therefore result in a yaw moment which increases the sideslip.  Expressed in linear control theory terms, this will be a pole in right hand plane when you plot the complex solution of the equations of motion. It is an unstable configuration.
Active Control
As Peter mentioned, it is possible to remain in control in this configuration by means of active control.  Active control tends to be somewhat tiring for a human operator if it is possible at all.  Incidentally, this kind of instability existed in the lateral axis of the 1903 Wright Flyer, which was configured with a canard of considerable proportion. It was reportedly quite tiring to keep stable.
CP ahead of CG
There are advantages to having a center of pressure ahead of the center of gravity, the chief being agility.  Back in control terms, the farther you move poles to the right, toward instability, the faster or "twitchy-er" the response.  The F-16 is configured this way and has been the standard of maneuverability for quite some time, requiring computers and fly-by wire for stability augmentation.
Control surfaces ahead of CG
It is also advantageous for maneuverability to have control surfaces ahead of the CG.  In this case it is for avoiding a feature of control termed "non-minimum phase" response.  For a conventional, tail-configured aircraft, when a climb is commanded, the tail is forced down, leading to a net reduction in lift until an increase of angle of attack is developed.  This is non-minimum phase response.  It was necessary to initially go the opposite direction from that which was desired.  In canard configurations, this is not the case, first the nose climbs, then everything climbs.
Put them together...
Forward control surfaces, forward center of pressure and a stability augmentation system with adequate dynamic pressure make for one heck of a maneuverable package.  This is a common recipie for tactical missiles.

Nice answer, I learned a bunch!

Well, it is. It has been done since maybe 160 Million years.
The Pterodactyloidea branch of flying saurians had long beaks, in most cases balanced by a large bony structure at the back of their heads, which provided lateral control. This is their only body part with noticeable side area, so no other part of their bodies could serve a similar purpose. Controlling direction like this helps to immediately change course to whatever the animal looks at.

Pterodactylus antiquus (picture source)
Since the head was ahead of their center of gravity, the configuration is statically unstable and needs continuous control corrections. On the other hand, it provides very quick responses. This works and has been proven several times by pterosaur-shaped flying models.
Another branch, the Rhamphorhynchoidea, had a tail which provided additional lateral and longitudinal control. Palaeobiologists are still arguing, however, whether the tip of the tail was oriented horizontally or vertically in flight.
In modern times weight and drag savings were the motivation for placing the fin at the tip of an airplane. The British space plane proposal HOTOL had such an actively controlled fin just on top of the fuselage nose. Also, many air-to-air missiles have their moveable control surfaces close to the tip, and those are balanced by bigger fins at the back. Both together make them canards in lateral and longitudinal control.

A plane whose control surfaces were ahead of the COG would very easily find itself in a situation where its heading and direction of motion differed so much that its control surfaces could no longer generate torque in the proper direction to set things right.  I would think that might also happen to a winged creature, but creatures could have a trick up their sleeve: a bird which found itself "flying" sideways through the air for whatever reason could likely change its attitude fairly quickly by drawing in its wings and shifting its mass around (something like a cat righting itself in midair).

I wonder to what extent flying creatures do or did that, and to what extent such abilities may lessen problems caused by control-system runaway?

@supercat: The flying models of Pterodactyls demonstrate how those animals might have flown, but will certainly fall short of the animal's possibilities of maneuverability by changing wing shape. But it is safe to assume that they were perfectly able to control their heading, quite like modern unstable and actively controlled systems.

It could also have held its head more like a Pelican!


text:
Why are emergency parachutes for pilots so heavy?
Parachute technology doesn't seem to have got much lighter in the past few decades.  It seems that most emergency parachutes designed for pilots still weigh about 15 lb.  And yet a Cirrus BRS designed to support over 10× the weight of a human is only 30lb and you can get reserve canopies designed for ultralights as light at 2lb.
Compare Mid-Lite 26' (7lb) with Gin Yeti UL (2.6lb) that has the same weight rating and sink rate and presumably better sink rate stability due to being cruciform. What's the advantage to the Mid-Lite?
Where are the 2-5 lb emergency parachutes for aircraft pilots?

Do the lighter canopies require more skill and training to use?  And are they certified for this use?

@TobySpeight: They shouldn't require more skill because they are the same design (round or cruciform) and similar sink rate. I'm not sure if any exist that are legal under 14 CFR 91.307(e), but if not, why not? What makes them safe for ultralights, but unsafe for bailing out of an aircraft?

The whole-aircraft CAPS parachute is not comparable because it's designed for a much higher vertical speed at impact. The landing gear and fuselage take the impact, often getting destroyed in the process, versus your legs when you bail out.

@user71659: That's an excellent point! Doubling the sink rate would result in a roughly 4-fold reduction in parachute surface area.

@user71659 thats a good point, I have a question however. Wouldn't a relatively heavier parachute(human case) make the sink rate higher hence a bigger impact than a relatively lighter parachute(aircraft case)?

@Gabe The extra 15lb doesn't change sink rate much because it's less than 10% the weight of an average human.

The simple answer is that paragliding reserves are not designed to handle terminal velocity, while pilot emergency parachutes are.
The longer answer is that they must conform to different standards and have different market pressures.
Standards
The Mid-Lite conforms to TSO C23c cat. B. This requires a safe operation in up to 150 knot deployment speed.
The Yeti confirms to EN 12491:2015. It includes a test for 60m/s (117 knots) opening shock.
I haven't looked into the standards otherwise, but I assume the TSO has more rigorous tests besides just the higher speeds.
Market Pressures
All paragliders must carry their entire aircraft on their backs (possibly for many miles) and often use two reserves, so there is a high market pressure for lighter reserves. This spurs R&D into highly specialized fabrics and optimized designs.
Pilots only need to carry their bailout rig to the plane, so they are not likely to want to pay a premium to shave a few pounds. There is little incentive for either the fabric manufacturers or the parachute manufacturers to invest in the R&D and certification costs.
PD Optimum story
One example of how niche parachute fabric can be is the PD Optimum (a skydiving reserve). I'm not sure if it's lighter, but it packs smaller, which is in big demand by recreational skydivers.
Performance Designs had to convince a fabric manufacturer to develop the fabric just for them, on the promise that they would buy a large quantity. Then they had to work with them to keep testing different types of fabric until they got one that might work. Then they had to design an entire new reserve model, because the new fabric changed too many flight characteristics for the old design to work. And then of course they had to certify it and convince an entire market of skydivers to trust it.


text:
Modern method to verify speed of a homebuilt aircraft
Summary:  In 2001, airspeed of homebuilt aircraft was calculated by flying in a ⊔-shape and using trigonometry to subtract wind effects.  Now that we have portable computers, is there a more modern method that is more accurate?
A paper published in 2001 by David Rogers outlines his "Horseshoe Heading Technique" which involves flying the aircraft in a ⊔-shape and recording GPS-derived groundspeeds so that you can then adjust for implied winds aloft to calculate the average TAS of the aircraft over the maneuver.
Now that we have significantly more advanced computer equipment in regular use, including AI, Extended Kalman Filters (the math behind AHRS), etc, are there more advanced ways of doing this that would use probabilistic methods to account for things such as pilot inaccuracy, wind variation during the flight, etc?  Or even ways that would allow for TAS to be calculated while performing arbitrary maneuvers?
The motivation for this question is that I'm considering making an app that calculates airspeed while taking into account lack of pilot precision.  I'm just not sure if anything like this exists already.

I'm totally confused as to what the distinction is: Aren't the calibration of airliners' air data computers tested using the Horseshoe Heading Technique? If not, what are they tested with? And if a certain method is used to verify the calibration in airliners, can that same method not be replicated in smaller aircraft?

Summary: I'm asking about test flying any size of aircraft and certified or non-certified. I just want to know what the options are for flight testing to verify airspeed calibration in general.

Well if there are differences in technique, I would love to hear about them. The most current I am aware of for both commercial and GA is the Horseshoe Heading Technique, so any information on any state-of-the-art improvements since then would be welcome.

To make it more explicit, we could say: How is the latest Boeing jet verifying its airspeed calibration in flight testing. I expect that most aircraft are being verifying their airspeed calibration in a similar way, but I could be wrong.

If it is truly desired for the system to work as the pilot is maneuvering arbitrarily, then it would appear that incorporating accurate aircraft heading data (not just direction-of-ground-track data) would be critical.  But that is easily available with today's technology--technology that is realistically available far beyond the realm of airliners, corporate jets, etc.

Apologies that I originally didn't have a very clear idea of my question.  John's answer helped me understand the difference in the way things are done for corporate testing vs homebuilt testing.  The standard procedure for airspeed testing in 2001 was the Horseshoe Heading Technique.  What is the standard procedure today?

On the newest experimental development programs they use what are called "Smart Booms", or Smart Air Data Test Probes, for the test a/c, which is a flight data probe or boom that doesn't have the traditional angle vanes etc, but just has a series of holes that allow dynamic pressure to be measured around the nose of the boom.
All of the parameters measured by the boom, dynamic/static pressures, angles of slip and attack etc, are derived by software.  Below is the Smart Boom (the orange bit) used on the developmental C Series (Airbus A220) that replaced the traditional long boom with vanes etc.

This is a Smart Probe developed for UAVs that produces very precise software-derived air data and may be what you have in mind.

The "Brauniger IQ Comp" variometer which is at least two or three decades old now is a rate-of-climb instrument for hang gliders.  It is capable of producing a wind direction and wind speed estimate any time the glider is engaged in circling flight, simply based on the ground track generated by a handheld-style GPS that interfaces with it.  (Obviously, there is an assumption that at least over the short run, the pilot is not making erratic changes in bank angle, so at least over the short run the glider is assumed to be describing round circles with respect to the airmass.)  If you know wind speed and direction, and you know ground speed and direction, then it is trivial to calculate TAS (especially when the glider happens to be going directly upwind or downwind.)  The much higher-tech computerized variometers of more recent design for sailplane usage undoubtedly have similar capabilities and more.  Therefore in any aircraft that spends a lot of time circling, or in any aircraft where the pilot is willing to fly a few sample circles without erratic changes in bank angle, it would seem trivial to use such instruments to come up with a wind calculation that is independent of any data from any airspeed probe.  This in turn, when compared with the ground track data, leads directly to a True Airspeed calculation that is independent of any data from any airspeed probe.  And when air temperature and pressure are taken into account, this leads directly to a calculation of  what the Indicated Airspeed ought to be.
Just as any modern soaring flight analysis software used to display and analyze actual flight tracks based on GPS position data alone can come up with an estimate of wind direction and speed and present a table of how this is varying both over altitude and over time. The same software can easily present a graph of groundspeed and direction of ground track. If the actual data from the airspeed indicator is also saved, a post-flight analysis of possible airspeed calibration errors should be entirely possible.
So no, this sort of thing is not something that can only exist in the world of Boeing airliners, corporate jets, etc.
As for a list of precisely which instruments or programs are best suited for, and often used for, actual real-time (or post-flight) calculation of errors in Indicated Airspeed -- that will be left to another answeree to complete the story.
(I guess I'm interpreting the question as one about what is the most state-of-the-art equipment that would be practically available to pilots of home-built aircraft, sailplanes, etc, and would avoid the need to fly horshoe patterns, etc.  A constant-banked circle, sustained over many revolutions, seems simpler and more redundant than a horseshoe pattern.  If it is truly desired for the system to work as the pilot is maneuvering arbitrarily, then it would appear that incorporating accurate aircraft heading data (not just direction-of-ground-track data) would be critical.  But that too is easily available with today's technology--technology that is realistically available far beyond the realm of airliners, corporate jets, etc.)


text:
Calculating airspeed by flying in a U shape: Horseshoe Heading Technique
I saw some equation in a log recently and I believe it went something as follows:
$v_1$ : flying North, $\ \ v_2$ : flying West, $\ \ v_3$ : flying South.
$$
\text{TAS} = \frac 1 2 \sqrt{v_1^2+v_2^2+v_3^2+\frac{v_2^2}{v_1^2+v_3^2}} = 199.7
$$
Which seems a little high for an RV-4 with O-320, even at 8,000ft and max power.
I may be mixing up the subscripts on the $\frac{v_2^2}{v_1^2+v_3^2}$ part, but those are the only subscripts that make sense by symmetry.
How does this airspeed calculation work?
I can imagine flying in a square and then taking the average $\frac 1 4 \left( v_N + v_W + v_S + v_E \right)$ (GPS-calculated groundspeeds) and I see the problem with that is that while the headwind and tailwind components cancel, the crosswind will not.  How does taking the euclidean distance between velocities fix this and what is the final term $\frac{v_2^2}{v_1^2+v_3^2}$?

I just found a paper on this that seems to correspond to the TAS measurement technique this test pilot was using:  I believe it is David Rogers Horseshoe Heading technique.
But I don't see how the equation presented above relates to any on that paper.
So what is the equation above?

For context, the reason we would not want to use the normal equation based on CAS, is because when flight testing a new aircraft we do not know for sure what the IAS→CAS conversion is, so it is necessary to determine it (or verify it, if building a kit). One way of doing that is to determine TAS independently (here using GPS and DR's HHT) and then calculate CAS from the TAS so that you can create your IAS→CAS correction table.

Comments are not for extended discussion; this conversation has been moved to chat.

It seems what they could have done here is to make a right triangle with an angle and a side, using cosine angle to determine TAS$^1$.
What they did was fly a 3 sided "horse shoe" pattern to determine wind component speed from drift, then applied this information to the headings into, across, and away from the northerly component.  The westerly component was across, with, and across for the 3 legs.
From there they applied the formula a$^2$ + b$^2$ = c$^2$ to determine the sides of each triangle.  That part is fairly straightforward.
Interestingly, the Air Force Test Pilot School suggested simply flying 2 legs perpendicular to the wind, while the National Test Pilot School flew 2 legs into and away from the wind.  The Horseshoe Heading Technique offers the advantage of verifying wind direction by flying one leg perpendicular to the other two (begging the question:  would not a box pattern be even better?)
The RV-4 looks rather sporty at 1500 lbs and easily makes 200 mph with the 180 horsepower O-360 engine at 75% power.  The O-320 is around 150 horsepower.  At max power it may be able to make 200.
The mathematics beyond building the triangles and determining the sides may be a bit more understandable by deriving wind components first, TAS component from each triangle next, and finally averaging all TAS results.
$^1$ even if not perfectly into or perpendicular to the wind, opposite TAS runs can still be averaged from cosine angle of course deflection × distance traveled (the hypotenuse).  The "horseshoe" does offer 3 sets of data, instead of 2.  The more runs you do, the more accurate the final averaged TAS will be.
As the aircraft moves with the airmass, it's TAS relative to the airmass is not affected by wind direction, so ground track and speed corrections can be made.

My understanding is that you could calculate TAS from CAS derived from the IAS you observe, but the derivation for your particular aircraft may differ slightly from the factory plans, so using the HHT with GPS to calculate TAS would give an entirely independent measure of TAS that you could use to verify your calibration equation.

I see that by moving the 1/2 inside, we are taking an average inside the square root, but I am confused about what that last term in that average represents.